CODEWITHSUNDEEP
javascriptphpjson
Thanh Trung
Thanh Trung

Reputation: 3804

Passing JSON to Javascript from PHP using direct output

Without using AJAX, how to correctly write a JSON string to JS from PHP. Example below, some case will break this code. I'm trying to find a perfect way to display json correctly, for both case "a" and "b"

Write the output JS to browser console, you'll see it breaks.

<?php
$var = array(
        'nokey',
        5 => 'xyz',
        'key' => '456',
        //bug
        "apostrophe ' xx" => 'quotes " xx',
        '\'' => "\"",
        'malicious backslash \ ' => 'double \\',
        "line break \n"
    );
$var = json_encode($var);
?>

<script>
    //bug
    var a = JSON.parse('<?php echo $var ?>');
    var b = JSON.parse("<?php echo $var ?>");
</script>

http://sandbox.onlinephpfunctions.com/code/5c860f978ddd6d196b15c58f55db20de34bcf72c

Upvotes: 0

Views: 59

Answers (2)

Ice76
Ice76

Reputation: 1130

You dont need to parse a JSON object when it is already JSON.

remove JSON.parse()

<?php
$var = array(
        'nokey',
        5 => 'xyz',
        'key' => '456',
        //bug
        "apostrophe ' xx" => 'quotes " xx',
        '\'' => "\"",
        'malicious backslash \ ' => 'double \\',
        "line break \n"
    );
$var = json_encode($var);
?>

<script>
    //bug
    var a = <?php echo $var ?>;
    var b = <?php echo $var ?>;
</script>

Upvotes: 2

samanime
samanime

Reputation: 26527

You need to also addslashes().

$var = addslashes(json_encode($var));

Then, once outputted, it'll be output with it's quotes slashed, allowing it to be parsed properly.

It doesn't matter if you are using single-quotes ('') or double-quotes (""), you can slash all the quotes and it'll be just fine.

Upvotes: 1

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